A Micro Spline cassette body for Vault hubs so you can run RF wheels with a Shimano MTB 12spd drivetrain. We were able to work around the geometry constraints of Micro Spline and fit the same large bearings used in other Vault cassette bodies to maintain RF performance and durability standards. For use with Shimano 12 speed MTB Cassettes only. Fits all Race Face VAULT rear hubs.